Substrate processing method

ABSTRACT

An outer covering wall ( 26 ) and an inner covering wall ( 27 ), which are capable of surrounding a rotor ( 24 ), can be horizontally moved. A wafer carrier waiting portion ( 30 ) is disposed right below the rotor ( 24 ). A wafer holding member ( 41 ) included in a wafer lifter ( 40 ) moves into a wafer carrier (C) containing wafers (W) and mounted on a stage ( 31 ) (sliding table  32 ) included in the wafer carrier waiting portion ( 30 ), lifts up the wafers (W) and transfers the wafers (W) to the rotor ( 24 ). The outer covering wall ( 26 ) or the inner covering wall ( 27 ) surrounds the rotor ( 24 ) to define a processing chamber. The wafers (W) held on the rotor ( 24 ) are subjected to a cleaning process in the processing chamber.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of Ser. No. 09/635,465, filed Aug. 11,2000, now U.S. Pat. No. 6,532,975, which is being incorporated in itsentirety herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate processing apparatus forprocessing substrates, such as semiconductor wafers, by a predeterminedprocess and a substrate processing method.

2. Description of the Related Art

A semiconductor device fabricating process employs a wafer cleaningapparatus that cleans semiconductor wafers, i.e., substrates, with acleaning liquid, such as pure water or a desired chemical liquid, toclean the wafers of contaminants including organic contaminants andmetallic impurities, and a wafer drying apparatus that removes liquiddrops from wafers for drying by means of an inert gas, such as N₂ gas,or a highly volatile and hydrophilic IPA vapor. Each of those knownwafer cleaning apparatus and wafer drying apparatus is of a batchprocessing type that processes a plurality of semiconductor waferssimultaneously in a wafer cleaning chamber or a wafer drying chamber.

Batch-type wafer cleaning apparatus are disclosed in, for example, U.S.Pat. Nos. 5,784,797, 5,678,320 and 5,232,328. The batch-type wafercleaning apparatus has a wafer carrying device that carriessemiconductor wafers into a wafer cleaning chamber formed therein.Generally, the wafer carrying device has a wafer chuck including a pairof gripping members. The wafer chuck grips a plurality of semiconductorwafers collectively. A lateral rotor is supported for rotation in thewafer cleaning chamber. The plurality of semiconductor wafers carriedinto the wafer cleaning chamber by the wafer carrying device are held byholding members mounted on the rotor in the wafer cleaning chamber. Moreconcretely, in the wafer cleaning apparatus disclosed in U.S. Pat. Nos.5,784,797 and 5,678,320, the wafer chuck of a wafer carrying device ismoved through a doorway formed in a front wall of a wafer cleaningchamber (a wall facing the wafer carrying device moving toward a wafercleaning chamber) into the wafer cleaning chamber from a side in frontof a wafer cleaning tank (from a side in front of the rotor), and wafersare transferred from the wafer chuck to the rotor.

A known wafer cleaning apparatus 400 shown in FIG. 32 has a wafercleaning tank 402 defining a wafer cleaning chamber 401. A rotor 405capable of holding semiconductor wafers W and of rotating can be movedthrough an opening 403 formed in the front end of the cleaning tank 402into and out of the cleaning tank 402. With the rotor 405 disposedoutside the wafer cleaning tank 402, the semiconductor wafers W aretransferred between the rotor 405 and a chuck having gripping members409 a and 409 b and attached to a carrying device. The rotor 405 ismoved into and out of the cleaning tank 402 and is rotated by a drivingmechanism 407. A shaft 480 is connected to the rotor 405.

A batch-type wafer drying apparatus is disclosed in, for example, JP-ANo. Hei 6-112186. This prior art batch-type wafer drying apparatus has awafer cleaning tank defining a wafer drying chamber and having an upperwall provided with a doorway. A lateral rotor is disposed in the wafercleaning chamber. A wafer holding hand capable of vertical movement forhandling semiconductor wafers is detachably mounted on the rotor. Thewafer holding hand is raised through the doorway to a position above thewafer cleaning tank to transfer semiconductor wafers between the waferholding hand and a wafer carrying device. When drying semiconductorwafers by this batch-type wafer drying apparatus, the semiconductorwafers are transferred from the wafer carrying device to the waferholding hand and the wafer holding hand is lowered to place the wafersin the wafer drying chamber. Subsequently, the wafer holding handholding the semiconductor wafers is mounted on the rotor to load therotor with the wafers, and the wafers are dried. After the wafers havebeen dried, the wafer holding hand is separated from the rotor, israised to a position above the wafer drying tank, and the dried wafersare griped by the wafer carrying device.

The wafer cleaning apparatus disclosed in U.S. Pat. Nos. 5,784,797 and5,678,320 need to secure a space sufficient for the wafer chuck tooperate in the wafer cleaning chamber and hence the size of the wafercleaning chamber must be increased accordingly. Since the wafer chuckoperates in a limited space in the wafer chamber, the operation of thewafer chuck must be carefully controlled so that the wafer chuck may notcollide against the wall of the wafer cleaning tank. Consequently, thewafer carrying device must execute complicated operations and a controlprogram for controlling the wafer carrying device is inevitablycomplicated.

Although the wafer chuck of the wafer cleaning apparatus 400 shown inFIG. 39 does not need to operate in a limited space, the wafer chuckmust be controlled so that the gripping members 409 a and 409 b of thewafer chuck may not collide against the holding members 406 of the rotor405. Consequently, a complicated control program is necessary forcontrolling the wafer chuck and the rotor 405.

In the wafer drying apparatus disclosed in JP-A No. Hei 6-112186, thewafer holding hand is always in contact with the semiconductor wafersthroughout a period in which the wafers are carried into the dryingchamber, dried and carried out of the drying chamber. Therefore, thereis the possibility that particles and the like adhering to and remainingon the wafer holding hand adhere again to the wafers to contaminate thedried wafers.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide asubstrate processing apparatus having a small substrate processingchamber and facilitating work for carrying substrates into and out ofthe substrate processing chamber, and a substrate processing method.Another object of the present invention is to provide a substrateprocessing apparatus and a substrate processing method capable ofpreventing the contamination of substrates.

To achieve the objects, the present invention provides a substrateprocessing apparatus including: a substrate processing portion at whicha plurality of substrates are treated by a process; a substrate waitingportion at which the substrates stand by for the process, the waitingportion being arranged below the processing portion; and a substratelifter including a substrate supporting member configured to support thesubstrates from below the substrates, the supporting member beingcapable of vertical movement, wherein the lifter supports the substratesplaced at the waiting portion and raises the substrates thereby movesthe substrates from the waiting portion to the processing portion, andwherein the lifter supports the substrates placed in the processingportion and lowers the substrates thereby moves the substrates from theprocessing portion to the waiting portion.

The present invention also provides a substrate processing apparatusincluding: a substrate processing portion at which a plurality ofsubstrates are-treated by a process; a substrate waiting portion atwhich the substrates stand by for the process, the waiting portion beingarranged above the processing portion; and a substrate lifter includinga substrate supporting member configured to support the substrates frombelow the substrates, the supporting member being capable of verticalmovement, wherein the lifter supports the substrates placed at thewaiting portion and lowers the substrates thereby moves the substratesfrom the waiting portion to the processing portion, and wherein thelifter supports the substrates placed in the processing portion andraises the substrates thereby moves the substrates from the processingportion to the waiting portion, and wherein the lifter is disposedoutside of the processing portion.

According to another respect of the present invention, a substrateprocessing method is provided, the method including the steps of:carrying a substrate container containing a plurality of substrates intoa container waiting portion disposed below a substrate processingportion for processing substrates; supporting the substrates containedin the substrate container, and raising the substrate to the processingportion disposed above the waiting portion; treating the substrates by aprocess at the substrate processing portion; supporting the substrateswhich have been treated and lowering the substrates into a substratecontainer; and carrying out the substrate container containing theprocessed substrates, which have been treated, from the waiting portion.

The present invention also provides a substrate processing methodincluding the steps of: holding a plurality of substrates by an arm andcarrying a substrates into a substrate waiting portion disposed above asubstrate processing portion; delivering the substrates from the arm toa supporting member; lowering the supporting member thereby moving thesubstrates to the processing portion; holding the substrates by asubstrate holding device provided at the processing portion; furtherlowering the supporting member thereby withdrawing the supporting memberfrom the processing portion; and treating the substrates by a process atthe substrate processing portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wafer cleaning apparatus in a firstembodiment according to the present invention;

FIG. 2 is a schematic plan view of the wafer cleaning apparatus shown inFIG. 1;

FIG. 3 is a sectional view of a cleaning unit included in the wafercleaning apparatus shown in FIG. 2;

FIG. 4 is a sectional view of a cleaning device included in the cleaningunit, in which an inner covering member is placed outside an outercovering member;

FIG. 5 is a sectional view of the cleaning device of the cleaning unit,in which the inner covering member is placed inside the outer coveringmember;

FIG. 6 is a sectional view taken on line A—A in FIG. 5;

FIG. 7 is a perspective view of a rotor included in the cleaning device;

FIG. 8 is a perspective view of arms, balance weights and projectionsshown in FIG. 7;

FIG. 9 is an enlarged perspective view of a vertical wall and conditionselecting members shown in FIG. 7;

FIG. 10 is a perspective view of the condition selecting members and theprojections in a state where a holding mechanism is in a releasingstate;

FIG. 11 is a perspective view of the condition selecting members and theprojections in a state where the holding mechanism is in a holdingstate;

FIG. 11A is a perspective view of another mechanism alternative to thatshown in FIGS. 9 to 11;

FIG. 12 is a plan view and a front elevation of a wafer containercarrier for carrying a wafer container between a stage included in aloading/unloading unit, and a wafer container waiting portion includedin the cleaning unit;

FIG. 13 is a side elevation of a wafer lifter included in the cleaningunit;

FIG. 14 is a block diagram of assistance in explaining an operation tobe executed when a pressure exceeding a predetermined level is appliedto wafers during the raising operation of the wafer lifter;

FIGS. 15 to 18 are typical views of assistance in explaining operationsof the wafer lifter for moving wafers to the rotor;

FIG. 19 is a sectional view of an outer covering member provided with adrip preventing device;

FIG. 20 is a perspective view of the drip preventing device shown inFIG. 19;

FIG. 21 is a perspective view of a wafer cleaning apparatus in a secondembodiment according to the present invention;

FIG. 22 is a schematic plan view of the wafer cleaning apparatus shownin FIG. 21;

FIG. 23 is a perspective view of essential portions of areceiving/delivering unit and a loading/unloading unit shown in FIG. 22;

FIG. 24 is a sectional view of a cleaning unit included in the wafercleaning apparatus shown in FIG. 21;

FIG. 25 is a schematic front elevation of an essential portion of thecleaning unit shown in FIG. 24;

FIG. 26 is a typical view of a first supporting member of a wafer liftershown in FIG. 25 supporting a wafer;

FIG. 27 is a typical view of a second supporting member of the waferlifter shown in FIG. 25 supporting a wafer;

FIGS. 28 to 35 are typical views of assistance in explaining a transferprocedure for transferring wafers between a wafer carrying arm and arotor;

FIG. 36 is a schematic sectional view of a wafer cleaning apparatus in amodification of the second embodiment;

FIG. 37 is a perspective view of a wafer lifter in a modification;

FIG. 38 is a perspective view of a wafer carrying arm in a modification;and

FIG. 39 is a perspective view of a conventional wafer cleaningapparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A wafer cleaning apparatus in a first embodiment according to thepresent invention will be described with reference to FIGS. 1 to 20. Thewafer cleaning apparatus carries out all the operations for carrying,cleaning, drying and delivering semiconductor wafers in a batchprocessing apparatus.

Referring to FIGS. 1 and 2, the wafer cleaning apparatus 1 has acontainer receiving/delivering unit 2, i.e., so-called “in/out port”,for receiving and delivering a wafer carrier C or a container containingwafers W, a cleaning unit 3 for cleaning wafers W, a loading/unloadingunit 4 interposed between the in/out port 2 and the cleaning unit 3 tocarry a wafer carrier C into and out of the cleaning unit 3, a wafercarrier cleaning unit 5 for cleaning wafer carriers C, and a wafercarrier storage unit 6 for storing a plurality of wafer carriers C. Thewafer cleaning apparatus 1 has also a power unit 7 and a chemical liquidtank box 8.

The in/out port 2 is provided with a stage 10 capable of supporting fourwafer carriers C thereon. A carrying path 11 is formed in the in/outport 2 on the stage 10 along a line on which wafer carriers C arearranged. A wafer carrier carrying mechanism 12 moves along the carryingpath 11 to carry a wafer carrier C placed on the stage 10 to theloading/unloading unit 4 and to carry a wafer carrier C from theloading/unloading unit 4 onto the stage 10. A wafer carrier C is capableof containing, for example, twenty-six wafers in a vertical position ina horizontal arrangement.

The loading/unloading unit 4 has a stage 13 for supporting a wafercarrier C thereon. A wafer carrier C transferred from the in/out port 2onto the stage 13 is carried by the wafer carrier carrying mechanism 12,which will be described in detail later, into the cleaning unit 3. Thewafer carrier carrying mechanism 12 carries the wafer carrier C from thecleaning unit 3 onto the stage 13. Since a wafer carrier C is carriedfrom the stage 10 to the stage 13 by turning an arm included in thewafer carrier carrying mechanism 12, the wafer carrier C placed on thestage 13 faces a direction opposite a direction in which the wafercarrier C faces on the stage 10. Therefore, the direction in which thewafer carrier C faces on the stage 13 is reversed by a reversingmechanism, not shown.

The cleaning unit 3 and the loading/unloading unit 4 are separated by apartition wall 14 provided with an opening 14 a through which a wafercarrier C is moved between the cleaning unit 3 and the loading/unloadingunit 4. The opening 14 a can be closed by a shutter 15. The shutter 15is closed while the cleaning unit 3 is in operation. The shutter 15 isopened when carrying a wafer carrier C from the loading/unloading unit 4into the cleaning unit 3 and when carrying a wafer carrier C from thecleaning unit 3 to the loading/unloading unit 4.

The wafer carrier cleaning unit 5 has a wafer carrier cleaning tank 16to clean an empty wafer carrier C which has been emptied by unloadingwafers W therefrom in the cleaning unit 3.

In the wafer carrier storage unit 6, empty wafer carriers C emptied byunloading wafers W to be cleaned therefrom are stored temporarily andempty wafer carriers C are stored therein to receive cleaned wafers W. Aplurality of wafer carriers C can be stored in stacks. The wafer carrierstorage unit 6 is provided with a wafer carrier moving mechanism fortransporting a desired one of the plurality of wafer carriers C storedin the wafer carrier storage unit 6 to the stage 10 and for placingwafer carriers C at desired positions in the wafer carrier storage unit6 for storage.

The cleaning unit 3 will be described with reference to FIGS. 3 to 6.

Referring to FIG. 3, the cleaning unit 3 is provided therein with asubstrate cleaning portion (i.e., a substrate processing portion) and asubstrate carrier waiting portion 30 (i.e., a substrate waitingportion). A cleaning device 20 is provided at the cleaning portion. Thewaiting portion 30 is disposed right under the cleaning device 20 tokeep a wafer carrier C temporarily. Furthermore, a wafer lifter 40 (i.e.so-called “wafer hand”) is provided in the cleaning unit 3. The waferlifter 40 raises wafers W standing by for processing in a wafer carrierC at the waiting portion 30 to move the wafers W to the cleaning device20. The wafer lifter 40 also returns the wafers W from the cleaningdevice 20 to the wafer carrier C kept at the waiting portion 30.

The cleaning device 20 removes a resist mask and an etch residue, suchas fragments of a polymer layer, remaining on wafers W processed by anetching process. The cleaning device 20 includes a vertical support wall18, a motor 23 having a drive shaft 23 a and fixedly held on the supportwall 18 in a horizontal position, a rotor 24 connected to the driveshaft 23 a of the motor 23, a cylindrical support tube 25 surroundingthe drive shaft 23 a of the motor 23, a cylindrical outer covering wall26 supported on the support tube 25, and a cylindrical inner coveringwall 27.

The outer covering wall 26 can be horizontally moved between a workingposition indicated by two-dot chain lines in FIG. 3 around the rotor 24and a back position indicated by continuous lines in FIG. 3 around thesupport tube 25. The inner covering wall 27 has a diameter smaller thanthat of the outer covering wall 26. The inner covering wall 27 can behorizontally moved between a working position around the rotor 24 asshown in FIG. 5 and a back position around the support tube 25 as shownin FIGS. 3 and 4. When wafers W are carried into and carried out of therotor 24, the outer covering wall 26 and the inner covering wall 27 areheld at their back positions as shown in FIG. 3. When the outer coveringwall 26 is at the working position and the inner covering wall 27 is atthe back position as shown in FIG. 4, a first chamber 51 (FIG. 4) isdefined by the outer covering wall 26, a vertical wall 26 a nearer tothe motor 23 and a vertical wall 26 b farther from the motor 23. Whenthe inner covering wall 27 is at the working position as shown in FIG.5, a second chamber 52 is defined by the inner covering wall 27 and thevertical walls 26 a and 26 b. The first chamber 51 and the secondchamber 52 are sealed by sealing mechanisms in closed spaces.

The vertical wall 26 a is attached to the support tube 25. The driveshaft 23 a is supported in bearings 28 on the support tube 25. Alabyrinth seal 29 is formed between the vertical wall 26 a and an endpart of the support tube 25 to prevent particles produced by the motor23 from entering the chambers 51 and 52. A support member 25 a ismounted on an end part of the support tube 25 on the side of the motor23 to support the outer covering wall 26 and the inner covering wall 27.

As shown in FIGS. 4 to 6, two spray pipes 54 provided with a pluralityof jetting holes 53 are attached in a horizontal position to an upperpart of the vertical wall 26 b opposite the vertical wall 26 a withrespect to the rotor 24. Pure water, IPA, N₂ gas or a chemical liquidsupplied from a source, not shown, can be sprayed by the spray pipes 54.When the outer covering wall 26 is at the working position and the innercovering wall 27 is at the back position as shown in FIG. 4, the spraypipes 54 are in an upper position of the first chamber 51 as shown inFIG. 6.

Two spray pipes 56 provided with a plurality of jetting holes 55 areattached in a horizontal position to the inner covering wall 27. Purewater, IPA or a chemical liquid supplied from a source, not shown, canbe sprayed by the spray pipes 56. As shown in FIG. 6, a N₂ gas jettingpipe 57 similar in construction to the spray pipes 56 is disposed nearthe spray pipe 56. When the outer covering wall 26 and the innercovering wall 27 are at their working positions as shown in FIG. 5, thespray pipes 54 extend in a space between the outer covering wall 26 andthe inner covering wall 27, i.e., outside the second chamber 52, and thespray pipes 56 extend in an upper position of the second chamber 52.

A first drain port 61 is formed in a lower part of the vertical wall 26b to drain used pure water, a used chemical liquid or used IPA from thefirst chamber 51 in a state shown in FIG. 4. A second drain port 62 isformed in the vertical wall 26 b at a position above the first drainport 61 to drain used pure water, a used chemical liquid or used IPAfrom the second chamber 52 in a state shown in FIG. 5. A first drainline 63 and a second drain line 64 are connected to the first drain port61 and the second drain port 62, respectively.

A first discharge 65 is formed in an upper part of the vertical wall 26b to discharge a gas from the first chamber 51 in a state shown in FIG.4. A second discharge port 66 is formed in the vertical wall 26 b at aposition below the first discharge port 65 to discharge a gas from thesecond chamber 52 in a state shown in FIG. 5. A first discharge line 67and a second discharge line 68 are connected to the first discharge port65 and the second discharge port 66, respectively.

The rotor 24 is capable of holding, for example, twenty-six wafers W ina horizontal arrangement. As shown in FIG. 7, the rotor 24 has a pair ofdisks 70 a and 70 b, first holding members 71 a and 71 b extendedbetween the pair of disks 70 a and 70 b so as to be symmetrical withrespect to a vertical plane including the axis of the rotor 24, secondholding members 72 a and 72 b extended between the pair of disks 70 aand 70 b so as to be symmetrical with respect to a vertical planeincluding the axis of the rotor 24, and a pair of holding mechanisms 73a and 73 b for fixedly holding wafers W on the rotor 24.

The first holding members 71 a and 71 b and the second holding members72 a and 72 b are provided with a plurality of grooves 75 for receivingperipheral parts of wafers W therein, respectively. At least one of theholding members 71 a, 72 b, 72 a and 72 b is provided with a pressuresensor.

As shown in FIGS. 7 and 8, the holding mechanism 73 a includes an arm 80a disposed on the inner side of the disk 70 a, a balance weight 81 adispose on the outer side of the disk 70 a, an arm 84 a disposed on theinner side of the disk 70 b, a balance weight 85 a disposed on the outerside of the disk 70 b, and a third holding member 83 a extended betweenthe arms 80 a and 84 a. The arm 80 a and the balance weight 81 a arefixedly connected to the opposite ends, respectively, of a shaft 89penetrating the disk 70 a for simultaneous turning. The arm 84 a and thebalance weight 85 a are fixedly connected to the opposite ends,respectively, of a shaft 89 penetrating the disk 70 b for simultaneousturning. The holding mechanism 73 b is similar in construction to theholding mechanism 73 a. The holding mechanism 73 b includes an arm 80 bdisposed on the inner side of the disk 70 a, a balance weight 81 bdispose on the outer side of the disk 70 a, an arm 84 b disposed on theinner side of the disk 70 b, a balance weight 85 b disposed on the outerside of the disk 70 b, and a third holding member 83 b extended betweenthe arms 80 b and 84 b. The arm 80 b and the balance weight 81 b arefixedly connected to the opposite ends, respectively, of a shaft 89penetrating the disk 70 a for simultaneous turning. The arm 84 b and thebalance weight 85 b are fixedly connected to the opposite ends,respectively, of a shaft 89 penetrating the disk 70 b for simultaneousturning. The third holding members 83 a and 83 b of the holdingmechanisms 73 a and 73 b are provided with a plurality of grooves 86 forreceiving peripheral portions of wafers W therein.

Stopping pins 87 project from the outer surfaces of the disks 70 a and70 b. When the third holding members 83 a and 83 b of the holdingmechanisms 73 a and 73 b are turned toward wafer holding positions,respectively, the outward turning of the balance weights 81 a, 81 b, 85a and 85 b is limited by the stopping pins 87 to prevent the balanceweights 81 a, 81 b, 85 a and 85 b from turning excessively outward andfrom touching the covering wall. As shown in FIG. 8, the balance weight85 a and 85 b supported on the disk 70 b adjacent to the vertical wall26 a are provided with curved projections 88 a and 88 b, respectively.

As shown in FIG. 9, an annular guide groove 90 is formed in the innersurface of the vertical wall 26 a on the side of the motor 23. Circularopenings 91 a and 91 b are formed in the vertical wall 26 a at positionson the guide groove 90 and respectively corresponding to the holdingmechanisms 73 a and 73 b, and cylindrical condition selecting members 92a and 92 b are fitted in the circular openings 91 a and 91 b so as to beturnable in the directions of the arrows θ. Curved slots 93 a and 93 bhaving the shape of an arc of a circle corresponding to the annularguide groove 90 are formed in the front surfaces of the conditionselecting members 92 a and 92 b, respectively. The condition selectingmembers 92 a and 92 b can be set in either an angular position in whichthe curved slots 93 a and 93 b form portions of the guide groove 90 asshown in FIG. 11 or an angular position in which the curved slots 93 aand 93 b extend across the guide groove 90 as shown in FIG. 10. Thecurved projections 88 a and 88 b of the balance weights 85 a and 85 bcan be fitted in the curved slots 93 a and 93 b, respectively. The stateof the holding mechanisms 73 a and 73 b can be selectively determined bythe angular positions of the condition selecting members 92 a and 92 b.

When the condition selecting members 92 a and 92 b are set so that thecurved slots 93 a and 93 b extend across the guide groove 90 as shown inFIG. 10 to set the balance weights 85 a and 85 b in a vertical position,the holding mechanisms 73 a and 73 b are set in a wafer releasing stateindicated by continuous lines in FIG. 7.

When the condition selecting members 92 a and 92 b are set so that thecurved slots 93 a and 93 b are continuous with the guide groove 90 asshown in FIG. 11, the balance weights 85 a and 85 b diverge upward, theholding mechanisms 73 a and 73 b are set in a wafer holding stateindicated by two-dot chain lines in FIG. 7. In this state, the curvedprojections 88 a and 88 b of the balance weights 85 a and 85 b are ableto move along the guide groove 90 and the curved slots 93 a and 93 bcontinuous with the guide groove 90, so that the rotor 24 is allowed torotate. Since the condition of the holding mechanism 73 a and 73 bremains unchanged regardless of the angular position of the rotor 24,the wafers W are not released. Therefore, it is possible to preventobstructing the supply of a cleaning liquid or a drying gas by wafers Wprojecting from the rotor 24 and to prevent damaging wafers W projectingfrom the rotor 24.

When the holding mechanisms 73 a and 73 b are in the wafer holdingstate, wafers W are held firmly by the first holding members 71 a and 71b, the second holding members 72 a and 72 b and the third holdingmembers 83 a and 83 b. As shown in FIG. 6, a triangle T1 formed byconnecting points on the first holding member 71 a, the second holdingmember 72 b and the third holding member 83 a at which each wafer W isheld is an acute triangle, and a triangle T2 formed by connecting pointson the first holding member 71 b, the second holding member 72 a and thethird holding member 83 b at which each wafer W is held is an acutetriangle. Therefore, wafers W can be securely held on the rotor 24during the rotation of the rotor 24.

FIG. 6 shows notched wafers W held on the rotor 24. When holding wafersW each provided with an orientation flat Wa indicated by a chain line asshown in FIG. 6 on the rotor 24, it is preferable to extend a supportrod S indicated by a chain line in FIG. 6 between the disks 70 a and 70b of the rotor 24. The support rod S in contact with the orientationflats Wa of the wafers W held on the rotor 24 prevents the unnecessaryturning of the wafers W on the rotor 24 during the rotation of the rotor24.

As shown in FIG. 11A, the vertical wall 26 a may be provided on itsinner surface with a circular guide rail 330 instead of the guide groove90. The circular guide rail 330 is provided with two gaps, and twoturnable rails 331 a and 331 b having the shape of an arc of a circlecorresponding to the circular guide rail 330 are placed in the gapsinstead of the condition selecting members 92 a and 92 b. The state ofthe holding mechanisms 73 a and 73 b can be selectively determined byselectively determining the angular positions of the rails 331 a and 331b. When the rails 331 a and 331 b are set so as to be continuous withthe guide rail 330, the holding mechanisms 73 a and 73 b are set in awafer holding state and the rotor 24 is allowed to rotate.

Referring again to FIG. 3, the wafer carrier waiting portion 30 isprovided with a stage 31. As shown in FIGS. 12(a) and 12(b), a wafercontainer carrier 35 or a carrier carrying mechanism, for carrying awafer carrier C between the waiting portion 30 and the loading/unloadingunit 4, includes a base 34 supported on the stages 13 and 31, two guiderails 33 laid on the base 34, and a sliding table 32 capable of movingalong the guide rails 33 between the stage 13 of the loading/unloadingunit 4 and the stage 31 of the waiting portion 30. The sliding table 32is moved by a cylinder actuator, not shown, to move a wafer carrier Cplaced on the sliding table 32 between the stages 13 and 31.

The sliding table 32 is provided with an opening in a portion thereofcorresponding to the wafer containing part of a wafer carrier C mountedthereon. The base 34 and the stage 31 are framed structures (skeletalstructures). Therefore, a wafer supporting member 41 of the wafer lifter40 is able to take out wafers W from and to put wafers W in a carrier C,which will be described later.

Referring to FIGS. 3 and 13, the wafer lifter 40 includes the wafersupporting member 41, a support bar 42 supporting the wafer supportingmember 41, and a driving device 43 for vertically moving the support bar42 to move raise and lower the wafer supporting member 41.

The driving device 43 includes a vertical threaded shaft 101, a steppingmotor 102 for rotating the threaded shaft 101, a guide rail 103 extendedin parallel to the threaded shaft 101, a sliding block 104 provided withan internal thread mating with the external thread of the threaded shaft101, and slides 105 that slide along the guide rail 103. The steppingmotor 102 drives the threaded shaft 101 for rotation to move the wafersupporting member 41 vertically. The threaded shaft 101, the slidingblock 104 and balls, not shown, form a ball screw.

The wafer supporting member 41 is provided with wafer holding grooves 41a in its upper surface. The number of the wafer holding grooves 41 a istwice the number of wafers W contained in a wafer carrier C, forexample, fifty-two. The pitch of the wafer holding grooves 41 a areequal to half that of the pitch of wafers W contained in a wafer carrierC. The wafer supporting member 41 can be horizontally shifted on a basemember 44 by a distance equal to the pitch of the wafer holding grooves41 a, i.e., half the pitch of wafers contained in a wafer carrier C.More concretely, as shown in FIG. 13, a piston rod connected to a pistonincluded in a cylinder actuator 106 and connected to the base member 44is moved axially to shift the wafer supporting member 41 horizontally bya distance equal to the pitch of the wafer holding grooves 41 a. Thus,cleaned wafers W can be received in the holding grooves 41 a differentfrom those in which the wafers W had been received before the wafers Wwere cleaned, so that possibility that the cleaned wafers W arecontaminated with particles and such adhering to the grooves 41 a inwhich the wafers W had been received before the same were cleaned can bereduced.

A piston rod connected to a piston included in a cylinder actuator 108is connected to the base member 44 and the cylinder actuator 108 isattached to the support bar 42. A pressure regulator 113 provided with apressure-relief valve is connected to the cylinder actuator 108. Whenraising wafers W by the wafer supporting member 41 to load the rotor 24with the wafers W, the pressure-relief valve of the pressure regulator113 opens to relieve pressure working on the piston of the cylinderactuator 108 upon the increase of pressure working on the piston of thecylinder actuator 108 beyond a predetermined limit, so that the pistonrod of the cylinder actuator 108 is retracted. Therefore, breakage ofthe wafers W when loading the rotor 24 with the wafers W can beprevented even if a control apparatus for controlling the wafer lifter40 should malfunction. A sensor 111 detects the lowering of the pistonrod. Upon the detection of the lowering of the piston rod, the sensor111 gives a detection signal to a controller 110, and then thecontroller 110 gives a command signal to an alarm device 112 to make thealarm device 112 generate an alarm.

As shown in FIG. 3, a wafer detector 115 including a plurality of pairseach of a light-emitting element and a light-receiving element disposedon the opposite sides, respectively, of a wafer carrying path isdisposed above the carrier waiting portion 30 to count the number ofwafers W as the wafers W pass by the wafer detector 115 and to findirregularly supported wafers (the so-called jump slots).

A series of operations of the wafer cleaning apparatus will bedescribed. Wafer carriers C each containing, for example, twenty-sixwafers W to be cleaned are carried onto the stage 10 of the in/out port2 by an operator or an automatic carrying device.

The wafer carrier carrying mechanism 12 carries one of the wafercarriers C placed on the stage 10 onto the sliding table 32 of thecontainer carrier 35 mounted on the stage 13 of the loading/unloadingunit 4. The wafer carrier C placed on the sliding stage 32 can be turnedthrough an angle of 180° in a horizontal plane by the reversingmechanism, not shown.

The shutter 15 is opened to open the opening 14 a of the partition wall14 and the sliding table 32 is moved onto the stage 31 of the carrierwaiting portion 30 of the cleaning unit 3. The wafer carrier C is kepton the stage 31 of the carrier waiting portion 30.

Subsequently, the outer covering wall 26 and the inner covering wall 27of the cleaning device 20 are set at their back positions, respectively,as shown in FIG. 3.

Then, as shown in FIG. 15, the wafer lifter 40 is actuated to raise thewafers W contained in the wafer carrier C mounted on the sliding table32 on the stage 31 of the carrier waiting portion 30 by the wafersupporting member 41. While the wafers W is being raised, the waferdetector 115 counts the wafers W and examines the wafers W to seewhether there is any jump slot. Then, as shown in FIG. 16, the wafers Ware brought into contact with the first holding members 71 a and 71 band the second holding members 72 a and 72 b of the rotor 24 with theirperipheral portions received in the grooves 74 of the holding members 71a, 71 b, 72 a and 72 b. In this state, the condition selecting members92 a and 92 b are turned so as to enable the holding members 83 a and 83b of the holding mechanisms 73 a and 73 b to be brought into contactwith the wafers W from below the same to hold the wafers W on the rotor24 as shown in FIG. 17. Subsequently, the wafer supporting member 41 islowered.

Then, the outer covering wall 26 is moved to the working position shownin FIG. 4 and a cleaning process is started. The empty wafer carrier Ckept on the stage at the wafer carrier waiting portion 30 is returned tothe loading/unloading unit 4 by the container carrier 35 and is carriedto the wafer carrier cleaning unit 5 by the wafer carrier carryingmechanism 12. The empty wafer carrier C is cleaned by the carriercleaning unit 5. A cleaned, empty wafer carrier C is carried from thewafer carrier storage unit 6 to the carrier waiting portion 30 by thewafer carrier carrying mechanism 12 and the container carrier 35. Thecleaned, empty wafer carrier C is kept on the stage of the waitingportion 30.

In the cleaning process, the inner covering wall 27 is moved to theworking position shown in FIG. 5 and a first cleaning step is executedin the second chamber 52; the rotor 24 is rotated at a predeterminedrotating speed and a chemical liquid (processing liquid) is sprayed bythe spray pipes 56 on the wafers W to remove a resist remaining on thewafers W for cleaning.

After the first cleaning step has been completed, the inner coveringwall 27 is retracted to the back position shown in FIG. 4, and then asecond cleaning step is executed in the first chamber 51; the rotor 24is rotated at a predetermined rotating speed and pure water is sprayedby the spray pipes 54 on the wafers W for rinsing.

Subsequently, a spin drying step is executed in the first chamber 51 ina state shown in FIG. 4, in which N₂ gas is jetted by the N₂ gas jettingpipe 57 while the rotor 24 is rotated at a rotating speed higher thanthat at which the rotor 24 is rotated in the second cleaning step.

After the cleaning and drying steps have been completed and the rotor 24has been stopped, the outer covering wall 26 is retracted to the backposition (the inner covering wall 27 is held at the back position) toexpose the rotor 24. Then, the wafer supporting member 41 of the waferlifter 40 is raised, the cleaned wafers W are transferred from the rotor24 to the wafer supporting member 41. The wafer supporting member 41 isshifted horizontally by a distance corresponding to the pitch of thewafer holding grooves 41 a before receiving the cleaned wafers W fromthe rotor 24 from a position at which the wafer supporting member 41held the wafers W before the wafers W are transferred to the rotor 24for cleaning. Consequently, the cleaned wafers W are received in thewafer holding grooves 41 a different from those in which the wafers Wsubjected to the cleaning process had been held.

In the state where the cleaned wafers W are held on the wafer supportingmember 41, the holding mechanisms 73 a and 73 b are in a condition shownin FIG. 17. Then, the condition selecting members 92 a and 92 b areturned to release the holding mechanisms 73 a and 73 b so that theholding mechanisms 73 a and 73 b are set in a condition shown in FIG.16. This releasing operation for releasing the holding mechanisms 73 aand 73 b can be carried out only when the projections 88 a and 88 b arein the curved slots 93 a and 93 b, respectively, and the releasingoperation cannot be performed when the projections 88 a and 88 b are inthe guide groove 90. Therefore, it is scarcely possible that the holdingmechanisms 73 a and 73 b are released and the wafers W fall off therotor 24 during the cleaning process.

The wafer supporting member 41 holding the cleaned wafers W is lowered.The wafer detector 115 counts the cleaned wafers W for confirmationwhile the cleaned wafers W are being moved downward. The wafers W arereceived and held in the wafer holding grooves of the wafer carrier Cwhen the wafer carrier C passes through the wafer carrier C kept on thestage 31 of the carrier keeping device 30.

Then, the wafer carrier C containing the cleaned wafers W is carried tothe loading/unloading unit 4 by the container carrier 35 and to thestage 10 of the receiving/delivering unit by the wafer carrier carryingmechanism 12. The operator or the automatic carrying device delivers thewafer carrier C to the next destination.

Since the wafers W are supported from below the same on the wafersupporting member 41 while the wafers W are moved vertically, the wafersW do not need to be gripped by a gripping device when carrying thewafers W into the processing chamber and hence any special space for theoperation of a gripping device need not be secured in the processingchamber. Therefore, the processing chamber of the wafer cleaningapparatus is compact.

Since the wafers W can be loaded on and unloaded from the rotor 24 onlyby the movement of the wafer supporting member 41 of the wafer lifter40, complicated control operations are unnecessary for loading thewafers W on and unloading the same from the rotor 24 of the cleaningdevice 20, the wafers W can be very easily loaded on and unloaded fromthe rotor 24, and the construction of the wafer cleaning apparatus canbe simplified.

Since the outer covering wall 26 and the inner covering wall 27 can bemoved between the working position and the back position and the spraypipes for spraying a chemical liquid and a rinsing liquid are placed inthe chambers defined by the covering walls 26 and 27, respectively,highly diversified cleaning processes can be carried out.

The outer covering wall 26 must be retracted before unloading the wafersW from the rotor 24 after the completion of the foregoing cleaningprocess. There is the possibility that the cleaning liquid drips whenthe outer covering wall 26 is retracted. It is preferable to connect aliquid collecting device 120 or a drip preventing device to the frontend of a lower part of the outer covering wall 26 as shown in FIG. 19 tocollect the liquid dripped from the outer covering wall 26 when theouter covering wall 26 is retracted. As shown in FIG. 20, the liquidcollecting device 120 includes a liquid tray 121 connected to the outercovering wall 26 so as to be movable and a drain tray 122 provided witha drain port 129. A liquid received by the liquid tray 121 is drainedinto a drain line through the drain tray 122. Two support members 123aand 123 b are fastened to the outer covering wall 26 with screws.Opposite end parts of a pair of guide shafts 124 a and 124 b aresupported on the support members 123 a and 123 b. A slide member 125 isfixed to the liquid tray 121 and is supported for sliding on the guideshafts 124 a and 124 b. A compression coil spring 126 or the pressingelement is extended between the slide member 125 and the support member123 b. When the outer covering wall 26 is moved to the working position,the compression coil spring 126 is compressed and the front end wall 127of the liquid tray 121 is pressed against an end part 130 of thevertical wall 26 b by the resilience of the compression coil spring 126.In an initial stage of retraction of the outer covering wall 26 afterthe completion of the cleaning process, the front end wall 127 of theliquid tray 121 is kept in contact with the end part 130 of the verticalwall 26 b by the resilience of the compression coil spring 126.Therefore, the liquid that drips from the front end of the outercovering wall 26 upon the separation of the outer covering wall 26 fromthe vertical wall 26 b can be received by the liquid tray 121 to preventthe dripping of the liquid. The liquid received by the liquid tray 121flows along the bottom wall 128 of the liquid tray 121 and the draintray 122 and is drained through the drain port 129 into the drain line.Note that an air cylinder actuator may be used as the pressing elementinstead of the coil spring 126.

Modifications of the cleaning apparatus in the first embodiment arepossible. For example, wafers taken out of a wafer carrier may becarried to carrier waiting portion 30, and then the wafers, standing byat waiting portion 30, may be raised to the rotor 24.

Although the cleaning apparatus in the first embodiment carries out thecleaning process using a chemical liquid in the second chamber 52defined by the inner covering wall 27 and carries out the rinsing anddrying processes in the first chamber 51 defined by the first coveringwall 26, the cleaning process may be carried out in the first chamberdefined by the outer covering wall 26, the rinsing process may becarried out in the second chamber 52 defined by the inner covering wall27 or the first chamber 51 and the second chamber 52 may be alternatelyused for the cleaning process.

Although the cleaning apparatus in the first embodiments is providedwith the outer covering wall 26 and the inner covering wall 27 to definethe two processing chambers, the cleaning apparatus may be provided withthree or more covering walls or a single covering wall.

Although the cleaning apparatus in the first embodiment exposes therotor 24 by retracting the outer covering wall 26 and the inner coveringwall 27 to their back positions, the vertical wall 26 b may be providedwith an opening covered and a cover covering the opening, and the rotor24 may be exposed by opening the cover and moving the rotor 24horizontally through the opening of the vertical wall 26 b.

A cleaning apparatus 201 in a second embodiment according to the presentinvention will be described hereinafter. Referring to FIGS. 21 and 22,the cleaning apparatus 201 has a receiving/delivering unit, i.e., anin/our port 202 for receiving and delivering a wafer carrier Ccontaining wafers W, a loading/unloading unit 203 that takes out notcleaned wafers W from a wafer carrier C and puts cleaned wafers W into awafer carrier C, a wafer carrier storage unit 204 for storing wafercarriers C, and a cleaning unit 206 provided with a wafer cleaningdevice 205. The cleaning apparatus 201 is provided with a wafer carriercarrying table 207 that carries a wafer carrier C, and a wafer carryingdevice 208 that grips and carries wafers W. The wafer carrier carryingtable 207 can be moved between the in/out port 202 and theloading/unloading unit 203. The wafer carrying device 208 is able tomove between the loading/unloading unit 203 and the cleaning unit 206,more specifically, a transfer position 234 in the cleaning unit 206.

The in/out port 202 is provided with a stage 211 for supporting wafercarriers C thereon. The stage 211 is provided with a plurality ofopenings at stations 212, 213, 214 and 215 in which wafer carriers C areplaced. Lower peripheral parts of wafer carriers C are supported on theedges of the openings of the stations 212 to 215, respectively.Normally, wafer carriers C containing not cleaned wafers W are placed atthe stations 212 and 213 and wafer carriers C containing cleaned wafersWare placed at the stations 214 and 215. The loading/unloading unit 203has a stage 216 provided with a station 217.

The wafer carrier carrying table 207 can be moved by a table movingmechanism 218 in directions parallel to a direction in which wafercarriers C are arranged on the stage 211, i.e., in directions indicatedby the arrows X in FIG. 22, and in directions parallel to a direction inwhich the in/out port 202, the loading/unloading unit 203 and thecleaning unit 206 are arranged, i.e., in the directions of the arrows Yin FIG. 22. The wafer carrier carrying table 207 is moved through one ofthe openings of the stations 212 to 215 and 217 to receive a wafercarrier C located at the corresponding station and carries the wafercarrier C to another station.

Referring to FIG. 23, a loading/unloading hand 220 is disposed under thestage 216 of the loading/unloading unit 203. The loading/unloading hand220 can be moved in vertical directions, i.e., in the directions of thearrows Z, and can be turned in a horizontal plane in the directions ofthe arrows θ by a lifting and turning mechanism, not shown. Theloading/unloading hand 220 is provided in its upper surface with aplurality of grooves 222 for receiving lower peripheral portions ofwafers W. When the loading/unloading hand 220 is raised, theloading/unloading hand 220 enters a wafer carrier C mounted on the stage216 through an opening formed in the bottom wall of the wafer carrier Cand lifts up a plurality of wafers W contained in the wafer carrier C.

A pitch changer 221 is mounted on the stage 216. The pitch changer 221is capable of rearranging the plurality of wafers W (twenty-six wafers)lifted up from the wafer carrier C by the loading/unloading hand 220 ata pitch equal to half a pitch at which the wafers W are arranged in thewafer carrier C to arrange the wafers W in a length equal to about halfthe length in which the wafers W are arranged in the wafer carrier C.

As shown in FIG. 22, the wafer carrying device 208 has stretchable wafersupport arms 224 a and 224 b capable of being moved toward and away fromeach other and a slide base 225 capable of sliding along a guide rail226 in the directions of the arrows X.

The wafer carrier storage unit 204 has wafer carrier keeping devices 227and 228 and a wafer carrier cleaner 229, which are arranged in a row.The wafer carrier keeping devices 227 and 228 are used for temporarilykeeping empty wafer carriers C emptied by taking out not cleaned wafersW therefrom in the loading/unloading unit 203 and for keeping cleanwafer carriers C for containing cleaned wafers W. The wafer carriercarrying table 207 carries a wafer carrier C into a vacant space in thestorage device 227 or 228 and carries out a wafer carrier C from thestorage device 227 or 228.

The wafer carrier carrying table 207 may carry a wafer carrier C intoand may take out a wafer carrier C from a specified place in either thestorage device 227 or 228. When the wafer carrier carrying table 207 isoperated in such a mode, the storage unit 204 is provided with a lifter,not shown, a the lifter transfers a wafer carrier C from the specifiedplace to a vacant place in the storage device 227 or 228 and transfers astored wafer carrier C from a storage place in the storage device 227 or228 to the specified place.

The cleaning unit 206 will be described with reference to FIGS. 24 to38. A cleaning device 20 provided at the cleaning unit 206 is identicalwith the cleaning device 20 employed in the first embodiment and hencethe description thereof will be omitted to avoid duplication.

In the cleaning unit 206, a wafer hand 233 or a wafer lifter is disposedbelow the rotor 24 of the cleaning device 20. The wafer hand 233 can bevertically moved between a wafer transfer position 234 in which wafers Ware put on and taken off the wafer hand 233 and a waiting position 235where the wafer hand 233 is kept for waiting. The waiting position 235,the rotor 24 and the transfer position 234 are arranged in that order.

Referring to FIGS. 24 to 26, the wafer hand 233 i.e., the substratemoving mechanism is equipped with a first support plate 300 (i.e., asubstrate support member) for supporting wafers W from below the same, asecond support plate 301 (i.e., a substrate support member) forsupporting wafers W from below the same, a lifting mechanism 302 mountedon the second support plate 301, and a base 303 on which the secondsupport plate 301 is mounted.

First support members 304 and 305 are fixed to laterally opposite endsof the first support plate 301, respectively. A plurality of grooves 309for receiving lower peripheral portions of wafers W are arranged at apredetermined pitch in the upper end surfaces of the first supportmembers 304 and 305 extending perpendicularly to the paper.

A lifting rod 307 included in the lifting mechanism 302 is connected tothe lower surface of the first support plate 300. Second support members308 and 309 are fixed to the upper surface of the second support plate301 so as to project into a space between the first support members 304and 305. The second support members 308 and 309 extend through andproject upward from the first support plate 300. A plurality of grooves310 for receiving lower peripheral portions of wafers W are arranged ata predetermined pitch in the upper end surfaces of the second supportmembers 308 and 309 extending perpendicularly to the paper.

When the lifting rod 307 of the lifting mechanism 302 is extended toraise the first support plate 300 so that the upper ends of the firstsupport members 304 and 305 are on a level above that of the upper endsof the second support members 308 and 309, lower peripheral portions ofwafers W can be supported on only the first support members 304 and 305.

When the lifting rod 307 of the lifting mechanism 302 is retracted tolower the first support plate 300 so that the upper ends of the firstsupport members 304 and 305 are on a level lower than that of the upperends of the second support members 308 and 309, lower peripheralportions of wafers W can be supported on only the second support members308 and 309 as shown in FIG. 27. Therefore, when the first supportmembers 304 and 305 are used for supporting not cleaned wafers W and thesecond support members 308 and 309 are used for supporting cleanedwafers W, it is possible to prevent contamination of the cleaned wafersW with particles fallen off the not cleaned wafers W and adhering to thefirst support members 304 and 305.

The base 303 of the wafer hand 233 is put on and connected to the upperend of a support rod 320. The support rod 320 is fixedly supported on alifting member 322 that is moved vertically along a guide rail 321,i.e., in the directions of the arrows Z in FIGS. 24 and 25. In FIG. 24,the wafer hand 233 indicated by continuous lines is at a lower waitingposition in the waiting position 235, and the wafer hand 233 indicatedby two-dot chain lines (233′) is in the transfer position 234 to receivewafers W from the wafer carrying device 208 or to transfer wafers W tothe wafer carrying device 208.

The base 303 has a horizontal top part 311 to which the second supportplate 301 is fixed, a vertical side part 312 supporting the top part 311in a horizontal position and a horizontal bottom part 313 supporting theside part 312 in a vertical position. A space 314 is formed between thetop part 312 and the bottom part 313. The wafer support arms 224 a and224 b of the wafer carrying device 208 are extended through the space314.

A series of operations of the wafer cleaning apparatus will bedescribed. Two wafer carriers C each containing, for example, twenty-sixwafers W to be cleaned are carried to the in/out port 202 and are placedat the stations 212 and 213 by, for example, an operator. The wafercarrier carrying table 207 carries the wafer carrier C placed at thestation 2-13 to the loading/unloading unit 203. In the loading/unloadingunit 302, the wafers W are unloaded from the wafer carrier C, and thetwenty-six wafers W are rearranged at a pitch equal to about half apitch at which the wafers W are arranged in the wafer carrier C by thepitch changer 221 in a wafer group. Subsequently, the wafer carrier Cplaced at the station 212 is carried to the loading/unloading unit 203,the twenty-six wafers W are unloaded from the wafer carriers C and thewafers W are rearranged at a pitch equal to about half a pitch at whichthe wafers W are arranged in the wafer carrier C in a wafer group. Thewafer groups each of the twenty-six wafers W are combined to form awafer group of the fifty-two wafers W arranged at a pitch equal to abouthalf a pitch at which the wafers W are arranged in the wafer carriers W.

The wafer carrying device 208 holds the wafer group of the fifty-twowafers and carries the same to the cleaning unit 206. The wafer carryingdevice 208 moves to the transfer position 234, i.e, a wafer waitingportion in the cleaning unit 206 as shown in FIG. 28.

The outer covering wall 26 and the inner covering wall 27 of thecleaning device are retracted to their back positions.

Then, as shown in FIG. 29, the wafer hand 233 is raised toward thetransfer position 234. The wafer lifting hand 233 with its componentsset in an arrangement shown in FIG. 26 is raised through spaces betweenthe corresponding holding members of the rotor 24.

As shown in FIG. 30, the wafer hand 233 raised into the transferposition 234 lifts up the not cleaned wafers W from the wafer supportarms 224 a and 224 b to receive the wafers W from the wafer carryingdevice 208. When the wafers W are thus transferred from the wafercarrying device 208 to the wafer hand 233, the wafer support arms 224 aand 224 b are on the level of the space 314 as shown in FIG. 24.Therefore, the wafer support arms 224 a and 224 b can be moved throughthe space 314 to retract the wafer carrying device 208 from the wafercleaning device 205 (FIG. 31).

Since the wafer holding arms 224 a and 224 b of the wafer carryingdevice 208 are moved only laterally and the wafer band 233 supports thewafer W from below the same, the transfer operation for transferring thewafers W from the wafer carrying device 208 to the wafer hand 233 is notobstructed and can be easily achieved. Therefore, the wafer carryingdevice 208 can be controlled by a control program of a simple algorithm,the wafer holding arms 224 a and 224 b do not need to be provided withany obstacle sensor and any complicated feedback control apparatus forcontrolling the wafer carrying device 208 is not necessary.

After the wafer carrying device 208 has been moved away from thecleaning unit 206 as shown in FIG. 32, the wafer hand 233 is lowered asshown in FIG. 33. As the wafer hand 233 is lowered toward the waitingposition 235, the wafers W are transferred from the wafer hand 233 tothe first holding members 71 a and 72 b and the second holding members72 a and 72 b of the rotor 24 as shown in FIG. 34. The wafer hand 233 isstopped temporarily or the lowering speed of the wafer hand 233 isreduced immediately before the wafers W come into contact with theholding members 71 a, 71 b, 72 a and 72 b for safety.

Then, the holding mechanisms 73 a and 73 b of the rotor 24 is operatedto bring third holding members 288 a and 288 b into engagement withperipheral portions of the wafers W so that the wafers W are heldsecurely on the rotor 24.

The outer covering wall 26, the inner covering wall 27, the rotor 24 andother components of the cleaning unit 206 are operated by the sameprocedure as that previously described in connection with the firstembodiment to carry out the cleaning process and the drying process.During the cleaning process and the drying process, the wafer hand 233is held in the waiting position.

After the completion of the cleaning process and the drying process, theouter covering wall 26 and the inner covering wall 27 are retracted totheir back positions and the wafers W are carried out of the wafercleaning device 205.

The components of the wafer lifting hand 233 are set in an arrangementas shown in FIG. 27 and the steps previously described with reference toFIGS. 28 to 35 are revised. Thus, the cleaned wafers W are held by thewafer carrying device 208. During those operations for holding thecleaned wafers W by the wafer carrying device 208, the wafer supportarms 224 a and 224 b of the wafer carrying device 208 are move onlylaterally. The wafer carrying device 208 carries the cleaned wafers W tothe loading/unloading unit 203. Then, the cleaned wafers W are put inwafer carriers C and the wafer carriers C are placed at the stations 214and 215 of the in/out port 202. Then, the wafer carriers C containingthe cleaned wafers W are delivered to the next destination.

Various modifications are possible in the cleaning apparatus in thesecond embodiment. For example, wafers W may be transferred from thewafer carrying device 208 to the wafer hand 233 at a position below therotor 24 as shown in FIG. 36. In this case, the wafer carrying device208 holding the wafers W is located at a position above the wafer hand233 and below the rotor 24 (i.e., wafer waiting portion), and then thewafers W are transferred from the wafer carrying device 208 to the waferhand 233 by a procedure similar to that described previously withreference to FIGS. 29 to 31. The procedure is different from thatdescribed in connection with FIGS. 29 to 31 only in the position wherethe wafers W are transferred from the wafer carrying device 208 to thewafer hand 233. The wafers W are transferred from the wafer hand 233 tothe rotor 24 by the same procedure as that described previously inconnection with the first embodiment with reference to FIGS. 16 to 18,in which the wafer hand 233 is used instead of the wafer supportingmember 41.

A wafer hand 340 shown in FIG. 37 may be employed instead of the waferhand 233. The wafer holding device 340 has a base 303 and a supportmember 341 slidable on the base 303. The support member 341 is providedin its upper surface with wafer holding grooves 342. The number of thegrooves 342 is twice (or an integral multiple greater than twice of) thenumber of the grooves 306 (309) formed in the first support members 304and 305 (the second support members 307 and 308). The pitch of thegrooves 342 is half that of the grooves 306 (309). Therefore, thecleaned wafers W can be received in the grooves different from those inwhich the not cleaned wafers W had been received before the same werecleaned by longitudinally shifting the support member 341 by a distanceequal to the pitch of the grooves 342, so that contamination of thecleaned wafers w with particles and such adhering to the grooves inwhich the not cleaned wafers W had been received before the same werecleaned can be prevented.

A wafer carrying device 350 shown in FIG. 38 may be employed instead ofthe wafer carrying device 208. The wafer carrying device 350 has wafersupport members 351 a and 351 b provided in their inner surfaces withwafer holding grooves 352. The number of the grooves 352 is twice (or anintegral multiple greater than twice of) the number of the groovesformed in the wafer support arms 224 a and 224 b of the wafer carryingdevice 208. The pitch of the grooves 352 is half that of the grooves ofthe wafer support arms 224 a and 224 b. Therefore, the cleaned wafers Wcan be received in the grooves different from those in which the notcleaned wafers W had been received before the same were cleaned bylongitudinally shifting the wafer support arms 351 a and 351 b by adistance equal to the pitch of the grooves 352, so that contamination ofthe cleaned wafers W with particles and such adhering to the grooves inwhich the not cleaned wafers W had been received before the same werecleaned can be prevented.

Although the invention has been described in its preferred embodimentsas applied to the cleaning apparatus, the present invention is notlimited thereto in its practical application. The present invention isapplicable to liquid application apparatus for applying a predeterminedcoating liquid to workpieces, CVD apparatus, etching apparatus and thelike. The substrates are not limited to semiconductor wafers, but may beLCD plates and such.

What is claimed is:
 1. A substrate processing method comprising thesteps of: carrying a substrate container containing a plurality ofsubstrates into a container waiting portion disposed below a substrateprocessing portion for processing substrates; supporting the substratescontained in the substrate container, and raising the substrates to theprocessing portion disposed above the waiting portion; treating thesubstrates by a process at the substrate processing portion; supportingthe substrates which have been treated and lowering the substrates intoa substrate container; carrying out the substrate container containingthe processed substrates, which have been treated, from the waitingportion; and wherein the substrates are supported on a first portion ofa substrate supporting unit when the substrates are being raised fromthe waiting portion to the processing portion before being treated, andthe substrates are supported on a second portion of the substratesupporting unit when the substrates are being lowered from theprocessing portion to the waiting portion after being processed, thesecond portion being different from the first portion.
 2. The methodaccording to claim 1, wherein the substrate supporting unit has a firstsupporting member serving as the first portion and a second supportingmember serving as the second portion, the first and second supportingmembers being adapted to move relatively.
 3. The method according toclaim 1, wherein the substrate supporting unit has a supporting memberprovided thereon with a first groove serving as the first portion and asecond groove serving as the second portion.
 4. A substrate processingmethod comprising the steps of: supporting a substrate located in aposition below a substrate processing portion by a substrate supportingmember, wherein the processing portion is a portion at which thesubstrate is to be treated; raising a substrate to the substrateprocessing portion, from below the processing portion by the substratesupporting member, and inserting the substrate supported by thesubstrate supporting member into a substrate holding device arranged atthe processing portion by raising the substrate; transferring thesubstrate from the supporting member to the substrate holding device;treating a substrate by a process, with the holding device beingsurrounded by a covering member that defines a processing chamber;transferring the treated substrate from the holding device to thesupporting member; and lowering the treated substrate to a positionbelow the processing portion by the supporting member.
 5. The methodaccording to claim 4 further comprising the steps of: lowering thesupporting member to a position below the processing portion, after thestep of transferring the substrate from the supporting member to theholding device; and maintaining the supporting member in a positionbelow the processing portion, while performing the step of treating thesubstrate.
 6. The method according to claim 4, wherein the step oftransferring the substrate from the holding device to the supportingmember includes the steps of: raising the supporting member supportingthe substrate from below the holding device; and holding the substratesupported by the supporting member by the holding device.
 7. The methodaccording to claim 4, further comprising the steps of: positioning thecovering member at a position away from the holding device so that thesupporting member is capable of accessing the holding device, whileperforming the step of transferring the substrate from the supportingmember to the holding device; positioning the covering member at aposition in which the covering member surrounds the holding device todefine the processing chamber, while performing the step of treating thesubstrate; and positioning the covering member at a position away fromthe holding device so that the supporting member is capable of accessingthe holding device, while performing the step of transferring thesubstrate from the holding device to the supporting member.
 8. Themethod according to claim 4, further comprising the step of: conveyingthe substrate to a first position below the processing portion, from asecond position remote from the first position; wherein the step ofraising the substrate is performed by raising the substrate thusconveyed to the first position below the substrate.
 9. A substrateprocessing method comprising the steps of: raising a substrate to asubstrate processing portion, at which the substrate is to be treated,from below the processing portion by a substrate supporting member;transferring the substrate from the supporting member to a substrateholding device arranged at the processing portion; treating a substrateby a first process, with the holding device being surrounded by a firstcovering member that defines a first processing chamber; treating asubstrate by a second process, with the holding device being surroundedby a second covering member that defines a second processing chamber;transferring the substrate treated by the first and second processesfrom the holding device to the supporting member; and lowering thetreated substrate to a position below the processing portion by thesupporting member.
 10. The method according to claim 9, wherein thefirst process is a liquid process by which the substrate is treated witha liquid, and the second process is a drying process.
 11. The methodaccording to claim 9, further comprising the steps of: positioning thefirst and the second covering members in positions away from the holdingdevice so that the supporting member is capable of accessing the holdingdevice, while performing the step of transferring the substrate from thesupporting member to the holding device; positioning the first coveringmember in a position in which the first covering member surrounds theholding device to define the first processing chamber, while performingstep of treating the substrate by the first process; positioning thesecond covering member in a position in which the second covering membersurrounds the holding device to define the second processing chamber,while performing the step of treating the substrate by the secondprocess; and positioning the first and the second covering members inpositions away from the holding device so that the supporting member iscapable of accessing the holding device, while performing the step oftransferring the substrate from the holding device to the supportingmember.
 12. The method according to claim 11, further comprising thestep of: positioning the first covering member in a position away fromthe holding device, while performing the step of treating the substrateby the second process.
 13. The method according to claim 9 furthercomprising the steps of: lowering the supporting member to a positionbelow the processing portion, after the step of transferring thesubstrate from the supporting member to the holding device; andmaintaining the supporting member in a position below the processingportion, while performing the step of treating the substrate.
 14. Themethod according to claim 9, wherein the step of transferring thesubstrate from the holding device to the supporting member includes thesteps of: raising the supporting member supporting the substrate frombelow the holding device; and holding the substrate supported by thesupporting member by the holding device.
 15. A substrate processingmethod comprising the steps of: supporting a substrate located in aposition above a substrate processing portion by a substrate supportingmember, wherein the processing portion is a portion at which thesubstrate is to be treated; lowering the substrate supported by thesupporting member by lowering the supporting member; transferring thesubstrate from the supporting member to a substrate holding devicearranged at the processing portion; lowering the supporting member to aposition below the processing portion; moving a covering member to aposition in which the covering member surrounds the holding device todefine a processing chamber; treating a substrate by a process in theprocessing chamber; moving the covering member to a position away fromthe holding device so that the supporting member is capable of accessingthe holding device; and raising the supporting member and transferringthe substrate treated by the process from the holding device to thesupporting member.
 16. A substrate processing method comprising thesteps of: supporting a substrate located in a position above a substrateprocessing portion by a substrate supporting member, wherein theprocessing portion is a portion at which the substrate is to be treated;lowering the substrate supported by the supporting member by loweringthe supporting member; transferring the substrate from the supportingmember to a substrate holding device arranged at the processing portion;lowering the supporting member to a position below the processingportion; moving a first covering member and a second covering member topositions in which the first and second covering members surround theholding device so that the first covering member defines a firstprocessing chamber; treating the substrate by a first process in thefirst processing chamber; moving the first covering member to a positionaway from the holding device so that only the second covering membersurrounds the holding device to define a second processing chamber;treating the substrate by a second process in the second processingchamber; moving the second covering member to a position away from theholding device so that the supporting member is capable of accessing theholding device; and raising the supporting member, and transferring thesubstrate treated by the first and second processes from the holdingdevice to the supporting member.